RawToTexture3D.cs

using UnityEngine;
using UnityEditor;

static class RawToTexture3D
{
    static Color IntToColor(uint b1, uint b2)
      => new Color((b2 + (b1 << 8)) / 65536.0f, 0, 0);

    [MenuItem("Tool/Raw to Texture3D")]
    static void ConvertRawToTexture3D()
    {
        var dims = new Vector3Int(256, 256, 113);

        var data = AssetDatabase
            .LoadAssetAtPath<TextAsset>("Assets/Editor/CThead.bytes").bytes;

        var tex = new Texture3D
            (dims.x, dims.y, dims.z, TextureFormat.RHalf, false);

        var offs = 0;

        for (var z = 0; z < dims.z; z++)
            for (var y = 0; y < dims.y; y++)
                for (var x = 0; x < dims.x; x++)
                    tex.SetPixel(x, y, z, IntToColor(data[offs++], data[offs++]), 0);

        tex.Apply();

        AssetDatabase.CreateAsset(tex, "Assets/temp.asset");
        AssetDatabase.SaveAssets();
    }
}